ABSTRACT

Sweating is the body’s most important mechanism for losing heat. Sweat is produced in response to overheating, and its evaporation from the skin surface results in cooling. The newborn baby is prone to thermal challenge, but this is usually in the form of cold stress. Heat production, a function of mass, is low. Heat loss, a function of surface area, is high. The newborn has a low mass-to-surface area ratio, so keeping warm is the major difficulty, not keeping cool. Congenital inability to sweat because of a deficiency of sweat glands is a feature of the condition hypohidrotic ectodermal dysplasia. Affected individuals are not usually prone to overheating in the newborn period-this becomes a problem in infancy and childhood. Hence, sweating in the newborn is a subject of interest rather than of any major importance. However, one form of sweating occurs in response to arousal and pain rather than temperature. This palmar-plantar or emotional sweating is a vestigial process in the human but is of particular interest because it provides an objective tool for quantifying a newborn infant’s response to procedural pain.